But speaking after playing a key role in his side's 25-8 Investec Super Rugby win over the Blues in Auckland on Friday, Mo'unga, the rugby equivalent of a smiling assassin, downplayed his leadership role in the side.
"I'm probably the most immature in the team and if you ask the lads out there I'm the one who's at the back of the meeting smirking or joking around about something, or you can't catch eye contact with me at a meeting or else you'll start laughing.
"But my job is to be really clear about what we're trying to do on Saturday and I think I can do that pretty well and fall into line with how we want to play and sometimes it goes good and sometimes it doesn't," he said.
That joker role was part of his raison d'être and he said if he didn't enjoy what he was doing he would have stopped playing rugby long ago.
Mo'unga enjoyed being back amongst the action against the Blues as he had found it difficult having to watch from the sofa at home while the Crusaders went down to the Chiefs a week earlier.
"Those games you want to be part of, the derby games, you remember those ones you grow up watching, those derby matches, especially playing here at Eden Park," he said.
He revelled in the first five-eighths' job of finding solutions similar to those that affected the Crusaders in Hamilton and he couldn't do much when watching from the couch.
"For me it was just really important to get my body right and focus on myself and be really selfish around my preparation to make sure that I was available for the Blues," he said.
That injury had meant he still wasn't comfortable goal-kicking but he was expecting to be back on the job next week against the Highlanders.
Mo'unga said the derbies were games that everyone got up for. The players were all mates, they knew each other from various levels of the game but he did remember the Blues and Crusaders clashes when growing up and the inevitable Carlos Spencer try in the corner at Lancaster Park.
He praised the efforts of the Crusaders pack who had managed to put the Blues' lineout and scrum under pressure.
"That doesn't just happen, that's the prep our forwards have done, it's Razor [Scott Robertson] and Jase Ryan putting in a plan to get that result," he said.
The Crusaders demonstrated again their ability to take full advantage of little moments and gain momentum from them.
"It's just like an Origin match this one," he said.
Mo'unga said David Havili, who filled in for him at first five-eighths a week earlier but who played fullback on Friday was in awesome form and was well in contention to regain an All Black jersey.
While he wasn't doing much different from the last few seasons, his form this year was making people realise how tough he was and how skilful and how much of a leader and influence he could be for the Crusaders and it was dangerous because Havili was realising that about himself as well, he said.